The popularity of wireless communication devices, such as mobile phones and Blue-tooth™ headsets, has over the last years grown significantly, amongst other things due to these types of communication devices being transportable, which means that they can be used virtually anywhere. Therefore, such communication devices are often used in noisy environments, the noise relating to for instance other people talking, traffic, machinery or wind noise. Consequently, it can be a problem for a far-end receiver or listener to separate the voice of the user from the noise.
It is well-known within the art to use a directional microphone to minimise the problems from noise. Such directional microphones have a varying sensitivity to noise as a function of the angle from a given source, this often being referred to as a directivity pattern. The directivity pattern of such a microphone is often provided with a number of directions of low sensitivity, also called directivity pattern nulls, and the directional pattern is typically arranged so that a direction of peak sensitivity is directed towards a desired sound source, such as a user of the directional microphone, and with the directivity pattern nulls directed towards the noise sources. Thereby, it is possible to maximise a voice-to-background-noise or signal-to-noise ratio of systems using such a directional microphone.
EP 0 652 686 discloses an apparatus of enhancing the signal-to-noise ratio of a microphone array, in which the directivity pattern is adaptively adjustable.
U.S. Pat. No. 7,206,421 relates to a hearing system beamformer and discloses a method and apparatus for enhancing the voice-to-background-noise ratio for increasing the understanding of speech in noisy environments and for reducing user listening fatigue.